TW202302677A - Two-part curable composition - Google Patents

Abstract

The present invention relates to a two-part curable composition comprising: • a first part (component A) comprising: • at least 50% by weight based on the total weight of the first part, of one or more alkyl cyanoacrylate monomer, said alkyl cyanoacrylate monomer comprising only one cyanoacrylate function; • one poly(2-cyanoacrylate) monomer having the following formula (I): wherein R is an organic moiety and n is an integer higher or equal to 2; • a second part (component B) comprising a (meth)acrylate component having at least two (meth)acrylate functions.

Description

two-part curable composition

The present invention is in the field of two-part curable compositions based on cyanoacrylates.

The invention also relates to the use of two-part curable compositions.

Adhesive compositions based on cyanoacrylate (CA) are well known, such as quick-drying adhesives or so-called "superglues". It is popular in many application areas and is used by consumers, professional technicians, and industrial assemblers. It is typically a solvent-free, 100% reactive material known for its ability to quickly form strong bonds on many different substrates.

1K or 2K (two-part) CA adhesives exist in the art. When describing the 2K method, it generally refers to the individual components or parts of the adhesive and/or its encapsulation, eg "Part A" and "Part B". Thus, if part A contains the CA composition in one compartment or reservoir, part B may contain the adhesive produced by mixing the two parts by any means for activation, reaction and/or modification A composition selected for its physical properties (plasticizing, coloring, toughening, etc.).

The two-part approach generally offers several benefits over one-part (1K) adhesives, but still needs improvement. There are different 2K CA adhesives on the market in terms of gap cure on various substrates and fast set times.

In the past, efforts have been made to improve the heat resistance of cured products of cyanoacrylate compositions, especially when exposed to temperatures of 80°C or higher. As the temperature gradually increases, the polycyanoacrylate adhesive begins to degrade and its physical properties deteriorate. Thus, the commercial application of cyanoacrylates exposed to high temperature conditions may have proven problematic and has thus been limited.

However, conventional CA adhesives have generally been limited in commercial applications where they may be exposed to heat because they do not also have "hot strength" (or high "use temperature") (ie, the ability to retain high tensile strength , advantageously above about 5 MPa, while being exposed to high temperatures typically above at least 100°C) and heat resistance (the ability not to degrade at high temperatures such as above 100°C). The "heat strength" or "use temperature" of an adhesive should not be confused with its "heat resistance". Heat resistance refers to the ability of the adhesive not to degrade after continuous exposure to high temperature, even after exposure to high temperature for a long period of time (for example, 3 days at 150° C.), as long as it is not simultaneously subjected to mechanical load at high temperature. For example, when metal substrates are joined by an adhesive based on unmodified ethyl cyanoacrylate, a rapid decrease in joint strength is observed at temperatures above 100°C. The heat resistance of the adhesive is an important characteristic, but it is not the only way to represent the performance of the joined parts in use in a hot environment.

This "hot strength" feature is important in many applications where the adhesive is subjected to high temperatures early in its life, under load, such as in the electronics or automotive fields. For some applications, heat intensity must be exhibited over a substantial period of time, for example more than 3 days at 150°C. Adhesives used, for example, in the manufacture of automotive parts in high-temperature processes, or for joining parts near the engine of a car, may be of interest.

There is therefore a need for novel CA adhesives that exhibit a good compromise between fast fixation times and good heat resistance and high hot strength for cured substrate assemblies.

其中R為有機部分且n為高於或等於2之整數； ● 第二部分(組分B)，其包含具有至少兩種(甲基)丙烯酸酯官能基之(甲基)丙烯酸酯組分。 The present invention relates to a two-part curable composition comprising: • a first part (component A) comprising: • at least 50% by weight of one or more alkyl cyanoacrylate monomers, based on the total weight of the first part , the alkyl cyanoacrylate monomer contains only one cyanoacrylate functional group; a poly(2-cyanoacrylate) monomer having the following formula (I):

wherein R is an organic moiety and n is an integer greater than or equal to 2; • a second part (component B) comprising a (meth)acrylate component having at least two (meth)acrylate functional groups.

In the context of the present invention, the term "about" is understood to mean that the measured value indicates that a certain variation in that value is accepted, typically +/- 5%.

The term "working lifetime" or "working time" ("WT") as used throughout this specification refers to the time between the first incorporation of the curing agent into the cyanoacrylate composition and the subsequent The period of time between the application of the activated composition to the part, i.e. the time period between the dispensing operations that the activated product resides or remains in the static mixing element itself (which serves to bind the adhesive components and acts as a dispensing nozzle) time. After the curing agent is blended, the curing process begins and continues when the adhesive is dispensed from the static mixing element.

The term "Open Time" ("OT") refers to the period of time in which an adhesive that has been activated and subsequently dispensed is still usable, i.e. when placed on a substrate as a drop, bead or volume ) form is substantially uncured when applied so that it cannot form an effective bond when it is used to join a second substrate. Open time thus describes the period of time during which the adhesive remains active but substantially uncured and ready to effectively join parts. An adhesive with a long OT refers to an adhesive that does not pre-set before assembling the part, even after dwelling on a single part for a relatively long time.

The term "fixture time"("FT") used in this specification is a measure of the speed of fitting or fixing, which is defined as the time it takes to fix the assembly, when the ambient temperature (approximately 25°C) and humidity (50% HR) for the entire evaluation, using a minimum amount of adhesive ( ^by -product droplet) on two matching substrates to have Performed with the ability to pause a 3 Kg weight for longer than 10 seconds.

The ranges disclosed in this specification include both the lower limit and the upper limit. For example, the expressions "within x to y" or "between x and y" include the limits x and y.

Component A - First Part Alkyl cyanoacrylate monomer Component A comprises at least 50% by weight, based on the total weight of the component A, of one or more alkyl cyanoacrylate monomers, the alkyl cyanoacrylate Monomers contain only one cyanoacrylate functionality.

其中R為C ₁-C ₁₈直鏈或分支鏈烷基，較佳C ₁-C ₁₀直鏈或分支鏈烷基，且甚至更佳C ₁-C ₈直鏈或分支鏈烷基。 In a preferred embodiment, the alkyl cyanoacrylate monomer has the general formula (II):

Wherein R is a C ₁ -C ₁₈ straight or branched chain alkyl, preferably a C ₁ -C ₁₀ straight or branched chain alkyl, and even more preferably a C ₁ -C ₈ straight or branched chain alkyl.

Alkyl cyanoacrylate monomers may be selected from the group consisting of: methyl cyanoacrylate, ethyl cyanoacrylate, n-propyl cyanoacrylate, isopropyl cyanoacrylate, n-butyl cyanoacrylate, cyano Secondary butyl cyanoacrylate, isobutyl cyanoacrylate, tertiary butyl cyanoacrylate, n-pentyl cyanoacrylate, 1-methylbutyl cyanoacrylate, 1-ethylpropyl cyanoacrylate, cyano Neopentyl cyanoacrylate, n-hexyl cyanoacrylate, 1-methylpentyl cyanoacrylate, n-heptyl cyanoacrylate, n-octyl cyanoacrylate, 2-octyl cyanoacrylate, 2-ethyl cyanoacrylate Hexyl ester, n-nonyl cyanoacrylate, n-decyl cyanoacrylate, n-undecyl cyanoacrylate and mixtures thereof.

Preferably, the alkyl cyanoacrylate monomer is selected from the group consisting of methyl cyanoacrylate, ethyl cyanoacrylate and mixtures thereof, and more preferably the alkyl cyanoacrylate monomer is ethyl cyanoacrylate.

Such monomers of formula (II) can be prepared by methods known to those skilled in the art, for example as described in patent US 2,467,927.

Some of these, such as ethyl cyanoacrylate (ECA) and methyl cyanoacrylate (MCA), are commercially available.

In the first part (component A) of the composition of the present invention, based on the total weight of the first part, the total content of alkyl cyanoacrylate monomers can be higher than or equal to 55% by weight, preferably higher than or equal to 60% by weight, more preferably higher than or equal to 70% by weight, and especially higher than or equal to 75% by weight.

In one embodiment, in the first part of the composition of the present invention, based on the total weight of the first part, the total content of alkyl cyanoacrylate monomers is 60% by weight to 99% by weight, preferably 65% by weight to 98% by weight and more preferably in the range of 70% to 95% by weight.

其中R為有機部分且n為高於或等於2之整數。 Poly ( 2 - cyanoacrylate ) monomer The first part (component A) comprises poly(2-cyanoacrylate ) monomer having the following formula (I):

wherein R is an organic moiety and n is an integer higher than or equal to 2.

In the above formula (I), n may be equal to 2, 3 or 4, and preferably, n is 2.

其中R為有機部分。 In a preferred embodiment, the poly(2-cyanoacrylate) monomer has the following formula (I-1):

where R is an organic moiety.

In one embodiment, in formulas (I) and (I-1), R can be alkylene, alkenylene, cycloalkylene, arylylene, alkoxyalkylene, aralkylene or Divalent residues of polymers such as polyolefins, polysiloxanes, polyesters, polyethers, polyurethanes, polyethylene glycols, polypropylene glycols. Preferably, R represents alkylene.

According to the present invention, the term "alkylene" covers both straight-chain and branched-chain alkylene groups. The same applies to the terms "alkenylene" and "alkoxyalkylene".

The poly(2-cyanoacrylate) monomer is preferably a compound of formula (I-1), wherein R represents an alkylene group, more preferably contains 2 to 30 carbon atoms, even more preferably 2 to 12 carbon atoms.

Even more preferably the poly(2-cyanoacrylate) monomer is a compound of formula (I-1), wherein R represents -(CH ₂ ) _m -, wherein m is 2, 3, 4, 5, 6, 8, 9 , 10 or 12. Suitable examples of such monomers include 1,10-decanediol dicyanoacrylate, 1,8-octanediol dicyanoacrylate, and 1,6-hexanediol dicyanoacrylate.

Poly(2-cyanoacrylate) monomers can be prepared as disclosed in WO94/15907, US2003194389, WO2015/150882 A1 or US6,096,848.

In the first part of the composition of the present invention, the total content of poly(2-cyanoacrylate) monomers may be higher than 3% by weight, preferably between 3% and 20% by weight, based on the total weight of the first part , and even better in the range of 5% by weight to 15% by weight.

Additives The first part of the composition may further contain at least one additive, for example selected from the group consisting of: thixotropic agents, thickeners, tougheners, accelerators, tackifiers, pigments, colorants, stabilizers, antioxidants , plasticizers and mixtures thereof.

Suitable stabilizers can be selected from the group consisting of free radical stabilizers, acid stabilizers and mixtures thereof.

The free radical stabilizer is usually a free radical polymerization inhibitor and is preferably selected from the group consisting of 4-methoxyphenol, hydroquinone, hydroquinone monomethyl ether, hydroxycresyl butyl ether, hydroxybenzoic acid Ether butyl ether, 4,4'-methylene bis(2,6-di-tertiary butylphenol) and mixtures thereof.

In the first part of the composition, based on the total weight of the first part, the total content of the free radical stabilizer may be 0.0001% by weight to 0.2% by weight, preferably 0.001% by weight to 0.1% by weight and more preferably 0.002% by weight to 0.06% by weight in the weight % range.

Acid stabilizers are generally inhibitors of anionic polymerization. Acid stabilizers may be selected from the group consisting of Bronsted acids, Lewis acids, and mixtures thereof. The acid stabilizer is preferably selected from the group consisting of methanesulfonic acid, p-toluenesulfonic acid, hydrofluoric acid, boron trifluoride, boron trifluoride etherate complex, fluoroboric acid, Sulfur dioxide and mixtures thereof.

In a preferred embodiment, the first part of the composition comprises methanesulfonic acid, sulfur dioxide, boron trifluoride etherate complex, hydroquinone and hydroquinone monomethyl ether and 4,4'-methylene Bis(2,6-di-tertiary butylphenol).

In the first part of the composition, based on the total weight of the first part, the total content of the stabilizer is generally 0.0001% by weight to 1% by weight, preferably 0.001% by weight to 0.8% by weight, and more preferably 0.0015% by weight to 0.7% by weight % range.

Typically, the tackifier may be selected from the group of aromatic carboxylic acids or anhydrides, and preferably from the group consisting of trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 3,3',4 , dianhydride of 4'-benzophenone tetracarboxylic acid, itaconic acid, itaconic anhydride, 3-butene-1,2,3-tricarboxylic acid and mixtures thereof.

Based on the total weight of the first part, the total content of the tackifier in the first part of the composition may be in the range of 0.02 wt % to 0.1 wt %, more preferably 0.03 wt % to 0.08 wt %.

Suitable accelerating agents/accelerators may be selected from calixarenes, crown ethers (e.g., 15 crown 5, 18 crown 6, dibenzo 18 crown 6 commercially available by Alfa Aesar), cyclodextrins and mixtures thereof .

Generally, the total content of the accelerator in the first part of the composition may be 0.01% to 0.8% by weight, preferably 0.05% to 0.5% by weight and more preferably 0.1% to 0.3% by weight, based on the total weight of the first part % range.

Suitable thixotropic agents may be selected from the group consisting of hydrogenated castor oil, polyamides, silicon dioxide, and mixtures thereof, optionally modified by reaction with amines.

Preferably, the thixotropic agent is silicon dioxide, more preferably selected from the group consisting of fumed silicon dioxide, hydrophobic fumed silicon dioxide (such as Aerosil ^® R202 commercialized by Evonik), hydrophilic fumed silicon dioxide Formed silica and precipitated silica.

Usually, based on the total weight of the first part, the total content of the thixotropic agent in the first part of the composition can be 2% by weight to 10% by weight, preferably 3% by weight to 8% by weight and more preferably 4% by weight to 7% by weight. in the weight % range.

The thickener/thickening agent suitable for use in the first part of the composition may be selected from those thickeners compatible with the host monomer. Examples of such thickeners include poly(meth)acrylates, cellulose acylate polymers such as cellulose acetate, polyvinyl acetate, partially hydrolyzed polyvinyl acetate, polyvinylpyrrolidone, Polyoxalates, polycaprolactones, polycyanoacrylates, vinyl acetate copolymers (e.g. with vinyl chloride), (meth)acrylates copolymers with butadiene and styrene, vinyl chloride and acrylonitrile Copolymers of ethylene and vinyl acetate, poly[butylene terephthalate-co-polyethylene terephthalate], copolymers of lactic acid and caprolactone, and mixtures thereof.

Such thickeners are well known to those skilled in the art and have been described in the prior art. Preferably, in the adhesive of the present invention, the thickener is selected from the group consisting of poly(meth)acrylate, polymethyl(meth)acrylate, polyvinylpyrrolidone, polyvinyl acetate , Partially hydrolyzed polyvinyl acetate, vinyl acetate copolymers and acrylated cellulose polymers. Thickeners suitable for the first part of the composition may be, for example, polymethylmethacrylate (e.g. ^Degacryl® M 449, Evonik), copolymers of vinyl acetate and vinyl alcohol (e.g. ^Levamelt® 900, Lanxess), vinyl chloride And copolymers of vinyl acetate (such as Vinnol ^® H 40-60, Wacker), copolymers of ethylene, vinyl acetate and maleic acid esters or partial esters (such as Vamac ^® G, DuPont), and mixtures thereof .

Usually, based on the total weight of the first part of the composition, the total content of the thickener in the first part of the composition can be 2% by weight to 10% by weight, preferably 3% by weight to 8% by weight and more preferably 4% by weight % to 7% by weight.

Tougheners/toughening agents suitable for use in the first part of the composition are block copolymers (e.g. polymethylmethacrylate-co-polybutylacrylate-co-polymethylmethacrylate); elastomers Rubber; Elastomeric polymers; Liquid elastomers; Polyester; Acrylic rubber; Butadiene/acrylonitrile rubber; Buna rubber; Polyisobutylene; Polyisoprene; Natural rubber; Synthetic rubber, such as Styrene/butadiene rubber (SBR); polyurethane polymers; ethylene-vinyl acetate polymers; fluorinated rubber; isoprene-acrylonitrile polymers; chlorosulfonated polyethylene; polyacetic acid Homopolymers of vinyl esters; core-shell rubber particles (commercially available for example from Arkema under the Clearstrength® XT100 tradename); and mixtures thereof.

Preferably, the first part of the composition does not comprise per-compounds, and more preferably does not comprise peroxides.

In a preferred embodiment, the first part of the composition comprises a thickener and a thixotropic agent, and it preferably further comprises a tackifier and at least one stabilizer.

Component A In a preferred embodiment, component A does not contain an alkoxyalkyl cyanoacrylate, such as methoxyethyl cyanoacrylate.

In a preferred embodiment, the first part of the composition comprises: - 60 wt% to 99 wt% of alkyl cyanoacrylate monomer(s) containing only one cyanoacrylate functional group; - 3 wt% to 20 wt% of a poly(2-cyanoacrylate) monomer having formula (I-1) as defined above - 2 wt% to 10 wt% thickener; - 2 wt% to 10 wt% thixotropic agent.

Component B Component B comprises a (meth)acrylate component having at least two (meth)acrylate functional groups.

The term "(meth)acrylate" refers to acrylate when the vinyl group of (meth)acrylate is substituted by -H atom α, or when the vinyl group is substituted by -CH ₃ (methyl) group α , which refers to methacrylate.

The (meth)acrylate component may have two (meth)acrylate functional groups (difunctional) or may have more than two (meth)acrylate functional groups (multifunctional, such as trifunctional or tetrafunctional) .

The (meth)acrylate component may be selected from (meth)acrylate monomers, oligomers, polymers and mixtures thereof.

Component B may comprise greater than 80 wt%, preferably greater than 90 wt%, even more preferably greater than 95 wt% of the total (meth)acrylate component, based on the total weight of the component B.

The (meth)acrylate component having at least two (meth)acrylate functional groups may be selected from the group consisting of: - Difunctional (meth)acrylate components such as butanediol di(meth)acrylate, hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylenediol Alcohol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trioxirane dimethacrylate, tricyclodecane dimethanol diacrylate, neopentyl glycol diacrylate, Bisphenol-A-Diacrylate, Bisphenol-A-Dimethacrylate, Ethoxylated Bisphenol-A-Diacrylate, Ethoxylated Bisphenol-A-Dimethacrylate, Propoxylated Bisphenol-A - diacrylate, (meth)acrylate functionalized oligomers and polymers and mixtures thereof; - Multifunctional (meth)acrylate components such as ginseng-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated Methylolpropane Triacrylate (TMPETA), Ethoxylated Trimethylolpropane Trimethacrylate, Neopentylthritol Tetraacrylate (PETA), Neopentylthritol Tetramethacrylate (PETMA), Dixin Penta(meth)acrylate, diperythritol hexa(meth)acrylate, (meth)acrylate functionalized oligomers and polymers and mixtures thereof; - mixtures thereof.

The (meth)acrylate functionalized oligomer or polymer may be a difunctional or multifunctional (meth)acrylate terminated urethane polymer or copolymer such as from SARTOMER as CN1993CG, CN2608, CN9210 Trademarked products.

Examples of (meth)acrylate components are readily available from well known suppliers such as Sartomer, Arkema and BASF.

The polyfunctional (meth)acrylate component may be composed of (meth)acrylic acid and diols or polyols such as butylene glycol, hexylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, triethylene glycol, esters prepared from methylolpropane, neopentyl glycol, neopentylthritol, bisphenol A or its alkoxylated derivatives. Its preparation process is well known to those skilled in the art.

In a preferred embodiment, the (meth)acrylate component having at least two (meth)acrylate functional groups is selected from the group consisting of: - Difunctional (meth)acrylate components such as butanediol di(meth)acrylate, hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylenediol Alcohol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trioxirane dimethacrylate, tricyclodecane dimethanol diacrylate, neopentyl glycol diacrylate, Bisphenol-A-Diacrylate, Bisphenol-A-Dimethacrylate, Ethoxylated Bisphenol-A-Diacrylate, Ethoxylated Bisphenol-A-Dimethacrylate, Propoxylated Bisphenol-A - diacrylates and mixtures thereof; - Multifunctional (meth)acrylate components such as ginseng-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated Methylolpropane Triacrylate (TMPETA), Ethoxylated Trimethylolpropane Trimethacrylate, Neopentylthritol Tetraacrylate (PETA), Neopentylthritol Tetramethacrylate (PETMA), Dixin Pentapenta(meth)acrylate, diperythritol hexa(meth)acrylate and mixtures thereof; - mixtures thereof.

Among the difunctional (meth)acrylate components, preferred are ethoxylated bisphenol-A-diacrylate, ethoxylated bisphenol-A-dimethacrylate, propoxylated bisphenol-A-diacrylate and mixtures thereof.

In one embodiment, the (meth)acrylate component is not polyethylene glycol di(meth)acrylate.

Among the polyfunctional (meth)acrylate components, ginseng-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), Ethoxylated Trimethylolpropane Triacrylate (TMPETA), Ethoxylated Trimethylolpropane Trimethacrylate, Neopentylthritol Tetraacrylate (PETA), Neopentylthritol Tetramethacrylate (PETMA) , diperythritol penta(meth)acrylate, dipenteoerythritol hexa(meth)acrylate and mixtures thereof, and even better from ethoxylated trimethylolpropane triacrylate (TMPETA) and ethyl Oxidized trimethylolpropane trimethacrylate.

In a preferred embodiment, component B comprises a mixture of: a bifunctional (meth)acrylate component and a multifunctional (meth)acrylate component. Based on the total weight of the sum of the difunctional (meth)acrylate component and the multifunctional (meth)acrylate component, the total content of the trifunctional (meth)acrylate component is more preferably higher than 50% by weight, More preferably higher than 70% by weight.

In preferred embodiments, the difunctional and multifunctional (meth)acrylate components are ethoxylated.

In a preferred embodiment, component B comprises: ● 5% to 40% by weight, more preferably 5% to 20% by weight of difunctional (meth)acrylate component; ● 40% to 95% by weight, more preferably 65% to 85% by weight of the multifunctional (meth)acrylate component.

Preferably, component B comprises: ● Ethoxylated bisphenol A dimethacrylate; and ● Ethoxylated trimethylolpropane triacrylate (TMPETA).

Component B of the initiator composition may comprise a nucleophilic initiator for the polymerization of cyanoacrylates.

The nucleophilic initiator can be selected from the group consisting of organic bases, salts with hard anions, reactive inorganic fillers, metal salts with organic counter anions, and mixtures thereof. The initiator is preferably an organic base.

Suitable organic bases are, for example, caffeine, theobromine, 5-chloro-2-methylbenzothiazole, 2-(morpholinothio)benzothiazole and tetrahydroquinoline.

Suitable salts with hard anions are, for example, choline chloride and benzalkonium chloride.

A suitable reactive inorganic filler is, for example, the hydrated calcium silicate known as Promaxon® D.

Suitable metal salts with an organic counter anion are, for example, calcium stearate, calcium acrylate, calcium methacrylate, magnesium acrylate, magnesium methacrylate, zinc acrylate, zinc methacrylate.

The second part may comprise the initiator at a concentration ranging from 0.05% to 1% by weight, and more preferably from 0.1% to 0.5% by weight, based on the total weight of the second part of the composition.

Component B of the additive composition may further contain at least one additive, for example selected from the group consisting of: thixotropic agents, thickeners, tougheners, accelerators, per-compounds, tackifiers, pigments, colorants, stabilizers agents, antioxidants, plasticizers and mixtures thereof.

Suitable stabilizers can be selected from the group consisting of free radical stabilizers, acid stabilizers and mixtures thereof.

The free radical stabilizer is usually a free radical polymerization inhibitor and is preferably selected from the group consisting of 4-methoxyphenol, hydroquinone, hydroquinone monomethyl ether, hydroxycresyl butyl ether, hydroxybenzoic acid Ether butyl ether, 4,4'-methylene bis(2,6-di-tertiary butylphenol) and mixtures thereof.

Based on the total weight of component B, in component B of the composition, the total content of free radical stabilizers can be 0% by weight to 0.5% by weight, preferably 0.001% by weight to 0.3% by weight and more preferably 0.01% by weight to within 0.1% by weight.

Acid stabilizers are generally inhibitors of anionic polymerization. Acid stabilizers may be selected from the group consisting of Bronsted acids, Lewis acids, and mixtures thereof. The acid stabilizer is preferably selected from the group consisting of methanesulfonic acid, p-toluenesulfonic acid, hydrofluoric acid, boron trifluoride, boron trifluoride etherate, fluoboric acid, sulfur dioxide and mixtures thereof.

In the second part of the composition, based on the total weight of the second part, the total content of the stabilizer can generally be 0% by weight to 1% by weight, preferably 0.001% by weight to 0.8% by weight and more preferably 0.0015% by weight to 0.7% by weight.

Typically, the tackifier may be selected from the group of aromatic carboxylic acids or anhydrides, and preferably from the group consisting of trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 3,3',4 , dianhydride of 4'-benzophenone tetracarboxylic acid, itaconic acid, itaconic anhydride, 3-butene-1,2,3-tricarboxylic acid and mixtures thereof.

The total amount of tackifier in the second part of the composition may range from 0% to 0.1% by weight, based on the total weight of the second part.

Suitable accelerating agents/accelerators may be selected from calixarenes, crown ethers (e.g., 15 crown 5, 18 crown 6, dibenzo 18 crown 6 commercially available by Alfa Aesar), cyclodextrins and mixtures thereof .

Typically, the accelerator may be present in the second part of the composition in an amount ranging from 0% to 0.8% by weight, based on the total weight of the second part.

Suitable thixotropic agents may be selected from the group consisting of hydrogenated castor oil, polyamides, silicon dioxide, and mixtures thereof, optionally modified by reaction with amines.

Preferably, the thixotropic agent is silicon dioxide, more preferably selected from the group consisting of fumed silicon dioxide, hydrophobic fumed silicon dioxide (such as Aerosil ^® R202 commercialized by Evonik), hydrophilic fumed silicon dioxide Formed silica and precipitated silica.

Usually, based on the total weight of the second part, the content of the thixotropic agent in the second part of the composition can be 2% by weight to 10% by weight, preferably 3% by weight to 8% by weight and more preferably 4% by weight to 7% by weight.

Thickeners/thickening agents suitable for use in the second part of the composition may be selected from those thickeners that are compatible with the monomers they contain. Among these may be mentioned poly(meth)acrylates, cellulose acylate polymers (eg cellulose acetate), polyvinyl acetate, partially hydrolyzed polyvinyl acetate, polyvinylpyrrolidone, polyoxalate , polycaprolactone, polycyanoacrylate, vinyl acetate copolymer (such as with vinyl chloride), (meth)acrylate copolymer with butadiene and styrene, copolymer of vinyl chloride and acrylonitrile, Copolymers of ethylene and vinyl acetate, poly[butylene terephthalate-co-polyethylene terephthalate], copolymers of lactic acid and caprolactone, and mixtures thereof.

Such thickeners are well known to those skilled in the art and have been described in the prior art. Preferably, in the composition of the present invention, the thickener is selected from the group consisting of poly(meth)acrylate, polyvinylpyrrolidone, polyvinyl acetate, partially hydrolyzed polyvinyl acetate, Vinyl acetate copolymers and cellulose acylate polymers. Suitable thickeners for the first part of the composition may be, for example, polymethylmethacrylate (e.g. ^Degacryl® M 449, Evonik), copolymers of vinyl acetate and vinyl alcohol (e.g. ^Levamelt® 900, Lanxess), Copolymers of vinyl chloride and vinyl acetate (e.g. Vinnol ^® H 40-60, Wacker), copolymers of ethylene, vinyl acetate and esters or partial esters of maleic acid (e.g. Vamac ^® G, DuPont), and its mixture. The cyanoacrylate itself can be added to the cyanoacrylate composition to bring about some degree of thickening. In addition, the tacky functionalized resin can also act as a thickener rather than any additional polymeric additive.

Percompounds are compounds containing the group O-O in the structure, such as peresters, perborates, persulfates, peracetals or peroxides.

Suitable per-compounds are, for example, tert-butyl perbenzoate (TBPB) or tert-butyl peroxide (TBP).

If present, the total content of per-compounds is preferably comprised between 0.1% and 1% by weight, preferably between 0.1% and 0.5% by weight, based on the total weight of the second part of the composition.

In a preferred embodiment, component B does not contain cyanoacrylate compounds.

Compositions The two-part composition may be dispensed from a package, such as a two-part syringe, or from a pot. The former is generally convenient for manual application and the first part: second part volume ratio may range from 1:1 to 10:1, more preferably 2:1 or 4:1. The two-part composition can also be dispensed using automated equipment, and the mixing ratio can be continuously adjustable from 1:1 to 10:1.

In a two-part composition, the first part: second part volume ratio may range from 1:1 to 10:1, preferably from 2:1 to 5:1, and even more preferably 4:1.

Preferred two-part curable compositions comprise ● The first part (component A), which contains: - 60 wt% to 99 wt% of alkyl cyanoacrylate monomer(s) containing only one cyanoacrylate functional group; - 3 wt% to 20 wt% of a poly(2-cyanoacrylate) monomer having formula (I-1) as defined above; - 2 wt% to 10 wt% thickener; - 2 wt% to 10 wt% thixotropic agent; ● The second part (component B), which contains: - 5% to 40% by weight, more preferably 5% to 20% by weight of a difunctional (meth)acrylate component; - 40% to 95% by weight, more preferably 65% to 85% by weight, of a multifunctional (meth)acrylate component; The difunctional and multifunctional (meth)acrylate components are preferably ethoxylated. - 0.01% to 1% by weight of nucleophilic initiator; - 0% to 5% thixotropic agent.

Syringe or syringe or dispenser head The present invention also relates to a syringe or syringe or dispenser head comprising a two-part curable composition as defined above.

Preferably, the syringe (or barrel) is a syringe (respectively a barrel) having two chambers, each chamber having a different volume, one for the first part of the composition and the other for the first part of the composition. In the second part of the composition, as defined above.

The first part of the composition is preferably placed in a larger volume chamber.

The adhesive is preferably prepared from a mixture of the two parts of the composition by manually depressing, or with the aid of a gun, the plunger of a syringe or syringe, forcing the contents of the chamber into the static mixer, and thereby At its outlet an adhesive according to the invention is obtained. In adhesives, the two components are advantageously intimately mixed.

For automatic dispensing, the adhesive is preferably prepared from a mixture of two parts of the composition by forcing them together into a valve and mixing element constituting a dispensing head so that a specific amount of the desired composition can be dispensed to each part.

Use of the composition The present invention also relates to the use of the two-part curable composition as defined above for joining substrates.

The invention also relates to a method for bonding substrates, comprising the following steps: - mixing together the two components of the two-part curable composition as defined above; - applying the mixture obtained above to at least one of the substrates, - Mate the substrates together for a time sufficient to allow a bond to form between the mated substrates.

The two-part adhesive composition of the present invention advantageously exhibits a good balance between the following properties: ● Fast fixation time: preferably less than 1 minute; ● High joint strength without gaps and even gaps of 2 mm; ● High heat aging resistance; ● High heat resistance when immersed in hot water (e.g. after immersion and continuous exposure to 60°C neutral water for 3 days, measured according to the joint strength on a pure ABS substrate); ● Resistant to organic solvents (eg as demonstrated by being highly insoluble in acetone for 24 hours at room temperature); ● High heat intensity (use temperature); ● Excellent shelf-life stability.

More specifically, the dual curable compositions according to the invention advantageously exhibit both "hot strength" and heat resistance.

EXAMPLES All of the following ingredients were used: Ethyl cyanoacrylate (ECA): Cartell Chemical Ltd. Methoxyethyl cyanoacrylate (MECA): Cartell Chemical Ltd. SO ₂ : Carburos Metalicos SA Sartomer SR 454: ethyl cyanoacrylate commercially available from Arkema Oxidized trimethylolpropane triacrylate Sartomer SR349: Ethoxylated bisphenol A dimethacrylate commercially available from Arkema Degacryl 449: Polymethylmethacrylate commercially available from Evonik Formula (I-1) synthesized according to US 9,670,145 (where R = -(CH ₂ ) ₆ -) dicyanoacrylate (1,6-hexanediol dicyanoacrylate) Aerosil® R202: Hydrophobic fumed silica commercially available from Evonik

The following products were obtained from Sigma Aldrich Merck: methanesulfonic acid, TBPB (tertiary butyl peroxybenzoate), hydroquinone, 4-methoxyphenol, itaconic acid, 2,2'-methylenebis( 6-tertiary butyl-4-methylphenol)

The following materials are used in the examples: Grit blasted mild steel (GBMS) lap shears (for all mechanical tests) Mild steel (MS) lap shears (for fixed time evaluation)

The efficacy of the composition was evaluated using the following method : Tensile shear strength test data reflect measurements after assembly of stacked lap shear pieces (Grit Blasted Mild Steel (GBMS) standard test piece) with a 250 ^mm2 contact area Joint strength (MPa), as measured according to ASTM D1002. The joined lap shears are first clamped and "rested" at room temperature (23°C ± 2°C) for 24 hours after assembly but before testing. Testing was performed using an Instron tensile tester operating at a crosshead speed of 1.3 mm/min.

Full volume cure (CTV) or full gap cure tests were performed using a small horseshoe-shaped spacer of 2 mm thickness around which the gel-like adhesive was coated.

The hot water resistance test was performed on the assembled GBMS lap shear samples that were completely submerged and exposed to hot water (60° C.) for 3 days, followed by standing at room temperature for 24 hours and subjected to destructive testing.

Heat resistance tests were performed on GBMS lap shears exposed to 150°C for 3 days, then allowed to cool to room temperature and allowed to stand for 24 hours, and then subjected to destructive testing.

Thermal strength ("service temperature") tests were performed on GBMS lap shears heated to specific individual temperatures of 100°C or 125°C or 150°C. The heated sample is insulated with an insulating fabric, and thermocouples are also placed in the fabric next to the substrate surface so the actual temperature can be tracked during destructive testing. The samples were subjected to tensile loading while maintained at elevated temperature during the actual destructive testing procedure.

Solvent resistance and insolubility were measured on bulk cured polymer (0.3 g) after immersing the sample in acetone (20 mL) for 24 hours. The insoluble fraction was filtered and dried at 60°C to constant mass and compared to the original mass or cured material.

Fixture time (FT) is the time during which a bond (250 mm ² ) is able to support a 3 kg load for 10 seconds at room temperature (23 ± 2°C) at 50% relative humidity (RH). FT is measured on mild steel (MS).

Example 1 : Two-Part Adhesive Composition Several parts A and two parts B were prepared according to the compositions indicated in Table 1 below. For the Part A formulation, the powdered PMMA thickener was first dissolved in the stabilized monofunctional CA monomer at or below 65°C. After the clear mixture had cooled to room temperature, the solid biscyanoacrylate was dissolved at room temperature and the viscosity of the mixture was then increased with fumed silica. A stabilizer is further added to component A. If necessary, add tackifier in sufficient amount to bring Component A to 100 wt%.

The Part B formulation was prepared without any specific precautions and without heating. Table 1 combination components C1 C2 (comparison) C3 (comparison) C4 (comparison) first part Alkyl cyanoacrylate monomer Ethyl cyanoacrylate (ECA) 78.84 wt% Ethyl cyanoacrylate (ECA) 47.47 wt% Ethyl cyanoacrylate (ECA) 53.37 wt% Ethyl cyanoacrylate (ECA) 78.84 wt% Methoxy cyanoacrylate (MECA) 31.37 wt% Methoxycyanoacrylate (MECA) 35.49 wt% Quinol 850 ppm 850 ppm 850 ppm 850 ppm 2,2'-Methylene bis(6-tertiary butyl-4-methylphenol) 200 ppm 200 ppm - 200 ppm Methanesulfonic acid 10 ppm 10 ppm 5 ppm 10 ppm 1,6-Hexanediol dicyanoacrylate formula (I-1), where R = -(CH ₂ ) ₆ - 10wt% 10wt% - 10wt% Degacryl 449 (PMMA) 6wt% 6wt% 6wt% 6wt% Aerosil® R202 (hydrophobic fumed silica) 5wt% 5wt% 5wt% 5wt% Iconic Acid (Tackifier) up to 100wt% up to 100wt% up to 100wt% up to 100wt% the second part SR349 23.88wt% 23.88wt% 23.88wt% - SR454 71.67 wt. % 71.67 wt. % 71.67 wt. % - caffeine 0.20wt% 0.20wt% 0.20wt% 0.20wt% Tertiary butyl perbenzoate 0.25wt% 0.25wt% 0.25wt% - Hydrophobic Fumed Silica 4wt% 4wt% 4wt% 4wt% Triacetin - 95.8wt%

The first and second parts of Table 1 were mixed and dispensed in a 4:1 volume ratio. The two portions were loaded into a 4:1 syringe equipped with a 4:1 static mixer. The first part is the part with the largest volume.

The performance of the adhesive composition is collected in Table 2 below. The rows in Table 2 refer to: - Tensile shear strength of lap shear of GBMS joints (both zero gap and 2 mm gap between substrates) after 24 hours at room temperature (23°C ± 2°C). - Tensile shear strength of the lap shear of the GBMS bond (zero gap between substrates) measured at room temperature (23°C ± 2°C) after exposure to 150°C for 3 days. - Tensile shear strength of lap shear of GBMS bond measured when the part is tested at 100°C (hot strength) (zero gap between substrates) - Tensile shear strength of the lap shear of the GBMS bond measured when the part is tested at 125°C (hot strength) (zero gap between substrates). - Tensile shear strength of lap shear of GMBS bond measured when the part is tested at 150°C (hot strength) (zero gap between substrates) - Tensile shear strength of lap shear (zero gap between substrates) of GMBS joint measured when testing parts at 125°C (hot strength) after exposure to 150°C for 3 days (first step To expose the part at 150°C for 3 days without load, then return to room temperature, then the second step is to test the part at 125°C (heat intensity)); - Tensile shear strength of lap shear (zero gap between substrates) of GMBS joint measured when testing parts at 150°C (hot strength) after exposure to 150°C for 3 days (first step To expose the part at 150°C for 3 days without load, then return to room temperature, then the second step is to test the part at 150°C (heat intensity)).

Table 2 combination FT ( seconds ) Cured material (%) insoluble in acetone ( 24 hours immersion ) Tensile Strength (MPa) Zero Gap GBMS Tensile strength (MPa) 2mm gap GBMS Tensile strength (MPa) GBMS ( heat resistance ) after 3 days at 150 °C Tensile heat strength (MPa) 100 ℃ GBMS Tensile heat strength (MPa) 125 ℃ GBMS Tensile heat strength (MPa) 125 ℃ GBMS after 3 days at 150 ℃ GBMS Tensile heat strength (MPa) 150 ℃ GBMS Tensile heat strength (MPa) 150 ℃ GBMS after 3 days at 150 ℃ GBMS Tensile strength (MPa) GBMS after 3 days in 60 ℃ water Composition C1 ( invention ) 45 81 16 9 18 8 6 5 2 2 13 Composition C2 ( comparison ) 40 92 16 9 15 4 2 nd 0 0 11 Composition C3 ( comparison ) 30 0 14 8 11 2.5 0 0 0 0 10 Composition C4 ( comparison ) 45 0 16 8 4 nd 0.5 0 0 0 nd nd: not determined

Composition C1 according to the invention advantageously exhibits the following: - Fast fixed time (45 seconds); - High bonding strength (16 MPa) without gap setting; - High bonding strength (9 MPa) under 2 mm gap; - High heat resistance (18 MPa after 3 days at 150°C); - High tensile shear strength while withstanding heat, as shown by hot strength values (8 MPa at 100°C, 6 MPa at 125°C, 2 MPa at 150°C), even after prolonged exposure to heat (after 3 days at 150°C, 5 MPa at 125°C, 2 MPa at 150°C) - High tensile shear strength after 3 days in water at 60°C, which shows good water resistance time (13 MPa).

Comparative compositions C2, C3 and C4 exhibited lower (or even zero) thermal strength than compositions according to the invention (8 and 6 MPa at 100°C and 125°C, respectively), at 100°C (C2: 4 MPa, C3: 2.5 MPa) and at 125°C (C2: 2 MPa, C3: 0 MPa, C4: 0.5 MPa).

Composition C1 according to the invention also exhibited higher heat resistance (18 MPa) compared to comparative compositions C2, C3 and C4 (15 MPa, 11 MPa and 4 MPa).

Compared to comparative compositions C2, C3 and C4 (0 MPa at 125°C for C3 and C4; 0 MPa at 150°C for C2, C3 and C4), at 125°C (5 MPa) and 150°C ( The composition C1 according to the invention also exhibits a higher heat strength after long-term heat exposure (3d150° C.) at 2 MPa).

Claims (20)

A two-part curable composition comprising: a first part (component A) comprising: at least 50% by weight of one or more alkyl cyanoacrylate monomers, based on the total weight of the first part, the cyano Alkyl acrylate monomers contain only one cyanoacrylate functional group; a poly(2-cyanoacrylate) monomer having the following formula (I):

wherein R is an organic moiety and n is an integer greater than or equal to 2; a second part (component B) comprising a (meth)acrylate component having at least two (meth)acrylate functional groups. The two-part curable composition of claim 1, wherein the alkyl cyanoacrylate monomer has the general formula (II):

Wherein R is C ₁ -C ₁₈ straight or branched chain alkyl, preferably C ₁ -C ₁₀ straight or branched chain alkyl, and even more preferably C ₁ -C ₈ straight or branched chain alkyl. The two-part curable composition according to any one of claim 1 or 2, wherein the alkyl cyanoacrylate monomer system is selected from the group consisting of: methyl cyanoacrylate, ethyl cyanoacrylate, cyanoacrylic acid n-propyl cyanoacrylate, isopropyl cyanoacrylate, n-butyl cyanoacrylate, secondary butyl cyanoacrylate, isobutyl cyanoacrylate, tertiary butyl cyanoacrylate, n-pentyl cyanoacrylate, cyano 1-methylbutyl cyanoacrylate, 1-ethylpropyl cyanoacrylate, neopentyl cyanoacrylate, n-hexyl cyanoacrylate, 1-methylpentyl cyanoacrylate, n-heptyl cyanoacrylate, cyano n-Octyl acrylate, 2-octyl cyanoacrylate, 2-ethylhexyl cyanoacrylate, n-nonyl cyanoacrylate, n-decyl cyanoacrylate, n-undecyl cyanoacrylate, and mixtures thereof. The two-part curable composition of any one of claims 1 to 3, wherein the total content of alkyl cyanoacrylate monomers in the first part is greater than or equal to 55% by weight, based on the total weight of the first part, It is preferably higher than or equal to 60% by weight, more preferably higher than or equal to 70% by weight, and especially higher than or equal to 75% by weight. The two-part curable composition according to any one of claims 1 to 4, wherein the poly(2-cyanoacrylate) monomer has the following formula (I-1):

where R is an organic moiety. The two-part curable composition according to any one of claims 1 to 5, wherein in formulas (I) and (I-1), R is alkylene, alkenylene, cycloalkylene, arylylene , alkoxyalkylene, aralkylene, or divalent residues of polymers such as polyolefins, polysiloxanes, polyesters, polyethers, polyurethanes, polyethylene glycols Or polypropylene glycol, R preferably represents an alkylene group. The two-part curable composition according to any one of claim 5 or 6, wherein in the formula (I-1), R represents -(CH ₂ ) _m -, wherein m is 2, 3, 4, 5, 6, 8, 9, 10 or 12. The two-part curable composition according to any one of claims 1 to 7, wherein the total content of poly(2-cyanoacrylate) monomer in the first part is greater than 3 based on the total weight of the first part % by weight, preferably in the range of 3% to 20% by weight, and even better 5% to 15% by weight. A two-part curable composition as claimed in any one of claims 1 to 8, wherein the first part of the composition further contains at least one additive, for example selected from the group consisting of: thixotropic agent, thickener, toughening agent additives, accelerators, tackifiers, pigments, colorants, stabilizers, antioxidants, plasticizers and mixtures thereof. The two-part curable composition according to any one of claims 1 to 9, wherein based on the total weight of the component B, the component B comprises more than 80% by weight, preferably more than 90% by weight, even more preferably more than 95% by weight of total (meth)acrylate components. The two-part curable composition according to any one of claims 1 to 10, wherein the (meth)acrylate component having at least two (meth)acrylate functional groups is selected from the group consisting of: Difunctional (meth)acrylate components such as butanediol di(meth)acrylate, hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol Di(meth)acrylate, polyethylene glycol di(meth)acrylate, trioxirane dimethacrylate, tricyclodecane dimethanol diacrylate, neopentyl glycol diacrylate, bis Phenol-A-Diacrylate, Bisphenol-A-Dimethacrylate, Ethoxylated Bisphenol-A-Diacrylate, Ethoxylated Bisphenol-A-Dimethacrylate, Propoxylated Bisphenol-A- Diacrylate, (meth)acrylate functionalized oligomers and polymers and mixtures thereof; Multifunctional (meth)acrylate components such as ginseng-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated trihydroxy Methylpropane Triacrylate (TMPETA), Ethoxylated Trimethylolpropane Trimethacrylate, Neopentylthritol Tetraacrylate (PETA), Neopentylthritol Tetramethacrylate (PETMA), Dineopentyl Tetrol penta(meth)acrylate, dipenteoerythritol hexa(meth)acrylate, (meth)acrylate functionalized oligomers and polymers and mixtures thereof; its mixture. The two-part curable composition according to any one of claims 1 to 11, wherein the component B comprises a mixture of a difunctional (meth)acrylate component and a multifunctional (meth)acrylate component, the component Part B preferably includes: 5% to 40% by weight, more preferably 5% to 20% by weight of a difunctional (meth)acrylate component; 40% to 95% by weight, more preferably 65% to 85% by weight of the multifunctional (meth)acrylate component. 2. The two-part curable composition according to any one of claims 1 to 12, wherein the difunctional and multifunctional (meth)acrylate component(s) are ethoxylated. The two-part curable composition according to any one of claims 1 to 13, wherein the component B comprises a nucleophilic initiator for cyanoacrylate polymerization, preferably selected from the group consisting of : Organic bases, salts with hard anions, reactive inorganic fillers, metal salts with organic counter anions and mixtures thereof. The two-part curable composition according to any one of claims 1 to 14, wherein the component B further contains at least one additive selected from the group consisting of: thixotropic agent, thickener, toughening agent, accelerator , overcompounds, tackifiers, pigments, colorants, stabilizers, antioxidants, plasticizers and mixtures thereof. The two-part curable composition according to any one of claims 1 to 15, wherein the first part: the second part volume ratio is in the range of 1:1 to 10:1, preferably 2:1 to 5:1, and even Even better 4:1. The two-part curable composition of any one of claims 1 to 16, comprising: The first part (component A), which comprises: 60 wt% to 99 wt% of an alkyl cyanoacrylate monomer(s) containing only one cyanoacrylate functional group; 3 wt% to 20 wt% of a poly(2-cyanoacrylate) monomer, which has the formula (I-1) as defined in any one of claims 5 to 7; 2 wt% to 10 wt% thickener; 2 wt% to 10 wt% thixotropic agent; The second part (component B), which comprises: 5% to 40% by weight, more preferably 5% to 20% by weight of a difunctional (meth)acrylate component; 40% to 95% by weight, more preferably 65% to 85% by weight of multifunctional (meth)acrylate component; The difunctional and polyfunctional (meth)acrylate components are preferably ethoxylated, 0.01% to 1% by weight of nucleophilic initiator; 0% to 5% thixotropic agent. 2. The two-part curable composition of any one of claims 1 to 17, wherein the component A does not comprise an alkoxyalkyl cyanoacrylate, such as methoxyethyl cyanoacrylate. A syringe or barrel or dispenser head comprising the two-part curable composition of any one of claims 1 to 18. A method for bonding substrates, comprising the steps of: mixing together the two components of the two-part curable composition of any one of claims 1 to 18; coating the mixture obtained above on at least one of the substrates, The substrates are mated together for a time sufficient to allow a bond to form between the mated substrates.